1. Field of the Invention
This invention relates generally to monitoring systems, and particularly to a system for sensing, alarming and correcting hazardous conditions arising from a variety of causes in a building environment including home residences.
2. Discussion of the Known Art
Recently, manufacturers of high-temperature plastics vent (HTPV) pipes joined with the United States Consumer Products Safety Commission (CPSC) to announce a recall program. Under the program, an estimated 250,000 HTPV pipe systems associated with gas or propane furnaces in consumers"" homes are being replaced free of charge. This is because HTPV pipes have been found to develop cracks and thus leak potentially fatal carbon monoxide (CO) gas. CO is a colorless, odorless gas produced by incomplete burning of carbon-based fuel, including natural gas and propane. The CPSC recommends that every home should be equipped with at least one CO sensor meeting all applicable standards. See CPSC Release #98-072 (Feb. 24, 1998).
Arrangements are known wherein a supply of a fuel such as natural or propane gas to an appliance (e.g., a water heater), is shut off by a valve upon detection of unburned gas above a certain threshold. See, for example, U.S. Pat. No. 1,609,930 (Dec. 7, 1926); U.S. Pat. No. 1,912,798 (Jun. 6, 1933); U.S. Pat. No. 2,532,214 (Nov. 28, 1950); and U.S. Pat. No. 3,236,284 (Feb. 22, 1966). The ""284 patent also discloses an alarm that is actuated upon a malfunction. See also U.S. Pat. No. 4,219,806 (Aug. 26, 1980).
U.S. Pat. No. 5,189,392 (Feb. 23, 1993) shows a heating system shut-off arrangement, which system uses an existing safety switch or fuel valve of a combustion unit. The combustion unit is shut down in response to an output from an environmental condition sensor which senses smoke, heat, gas, flame and/or rate of heat rise. U.S. Pat. No. 5,280,802 (Jan. 25, 1994) also shows gas appliance detection apparatus for use with a water heater. The apparatus uses two sensors to detect gas spillage on account of a flue restriction, or a gas fume backup at the flame portion of the heater.
U.S. Pat. No. 4,338,526 (Jul. 6, 1982) and U.S. Pat. No. 4,464,651 (Aug. 7, 1984) show a home security/garage door operating system wherein a garage door is opened in response to detection of carbon monoxide above a preset level. Further, U.S. Pat. No. 5,576,739 (Nov. 19, 1996) discloses a carbon monoxide safety system capable of decreasing the concentration of CO by opening a garage door, or by interrupting power to a furnace.
A central monitor for a home security system is shown in U.S. Pat. No. 4,581,606 (Apr. 8, 1986). While the system includes a number of sensors relating to heat, intrusion and appliance operation, there is no provision of any mechanism for corrective action such as, e.g., interrupting a water or fuel supply to a malfunctioning appliance.
Notwithstanding the above disclosed arrangements, there remains a need for a system that (a) allows a property owner to monitor a number of different utilities and appliances for dangerous conditions such as, e.g., the presence of CO, unusual levels of water, or excessively high or low temperatures at selected locations, (b) alarms the condition and provides relevant information to the owner or other responsible persons, e.g., via a telephone link, and (c) initiates certain corrective measures specific to the alarmed condition or conditions.
According to the invention, a monitor and control system includes a processor for responding to alarm signals representing different hazardous conditions in an environment having a number of utility service supply lines. One or more environmental condition sensors are coupled to corresponding inputs of the processor, and each sensor is operatively associated with one or more of the service supply lines. Each sensor produces an alarm signal in response to a hazardous condition attributable to an associated service supply line, and each supply line is provided with a control device that is coupled to a corresponding output of the processor. The processor is configured to produce one or more output signals as desired in response to an alarm signal at a given input of the processor, and each control device is constructed and arranged to disable its associated supply line with respect to a sensed hazardous condition in response to a corresponding output signal from the processor.